Merge branch 'linux-4.13' of git://github.com/skeggsb/linux into drm-fixes

two more fixes for issues nouveau found in fedora 26.

* 'linux-4.13' of git://github.com/skeggsb/linux:
  drm/nouveau/bar/gf100: fix access to upper half of BAR2
  drm/nouveau/disp/nv50-: bump max chans to 21